US 5,309,709 AGranted

Low emission combustion system for a gas turbine engine

AssigneeSolar Turbines Incorporated

InventorsPhilip J. Cederwall, Kenneth O. Smith, Graham E. Ogborne

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Abstract

The known control systems for reducing NOx in the combustion systems of past gas turbine engines has incorporated a variety of expensive and complicated techniques to reduce the NOx level. The present apparatus reduces the formation of NOx within the combustion zone by controlling the air portion of the air/fuel ratio. The present apparatus includes a device for controllably varying the quantity of compressed air directed into a manifold resulting in controlling the air to a plurality of injection nozzles and into a combustor. A throttling mechanism moves between an open position and a closed position varying the flow rate of compressor air to the combustor apparatus provides an economical, reliable and effective method for reducing and controlling the amount of nitrogen oxide (NOx) carbon monoxide (CO) and unburned hydrocarbon (UHC) emitted from the gas turbine engine.

Claims26

Dependent claims

A control system for reducing the formation of exhaust emissions during operation of a gas turbine engine, the engine including a source of compressed air, a combustor and a turbine arranged in serial order, a plurality of fuel injection nozzles for directing a combustible fuel and compressed air into the combustor, each fuel injection nozzle having a chamber therein in which air and fuel is premixed prior to entering into the combustor;

said control system comprising:
means for directing a portion of the flow of compressed air exiting the compressor section through the plurality of injection nozzles into the combustor in an amount sufficient, with the addition of an appropriate amount of fuel, to support full fuel operation of the gas turbine engine at rated speed, said means for directing including a manifold encircling the gas turbine and positioned externally thereof, said manifold being in communication with the flow of compressed air exiting the compressor section by way of a duct positioned between the manifold and the gas turbine engine, each of said plurality of injection nozzles being in communication with the manifold;
means for controllably varying the amount of air directed into the combustor by directing a portion of the air from the compressor section into the manifold and into each of the plurality of injection nozzles when the engine is operated at power levels between low fuel and high fuel conditions, said means for controllably varying being operatively positioned within the duct between the source of compressed air and the manifold.

A gas turbine engine having a control system for reducing the formation of exhaust emissions during operation of a gas turbine engine, the engine including a source of compressed air, a combustor and a turbine arranged in serial order, a plurality of fuel injection nozzles directing a combustible fuel and compressed air into the combustor, each of said plurality of fuel injection nozzles having a chamber therein in which air and fuel is premixed prior to entering into the combustor;

said control system comprising:
means for directing air from the source of compressed air through the plurality of injection nozzles into the combustor in an amount sufficient, with the addition of an appropriate amount of fuel, to support full fuel operation of the gas turbine engine at rated speed, said means for directing including a manifold encircling the gas turbine, air exiting the compressor section by way of a duct positioned between the manifold and the gas turbine engine, each of said plurality of injection nozzles being in communication with the manifold;
means for controllably varying the amount of air directed into the combustor by directing a portion of the air from the compressor section into the manifold and into each of the plurality of injection nozzles when the engine is operated at power levels between low fuel and high fuel conditions, said means for controllably varying being operatively positioned between the source of compressed air and the manifold.

Dependencies are inferred from the claim text.